William g



(No Model.) 7

W. G. SMITH.

BALANCED SLIDE VALVE; No. 298,512. ET Patented May 13, 1884.

' all WITNESSES INVENTOR 1 w M m. Y K I 3 fw ATTORNEYS.

N, PETERS. mlo-Limo n mr, Washington, D. C

NITED STATES WILLIAM G. SMITH, OF NEW YORK, N. Y.

BALANCED SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 298,512, dated May 13, 1884.

Application filed January 29, 1884. (No model.)

1'0 all whom it may concern: 1

Be it known that I, WILLIAM G. SMITH, of the city, county, and State of New York, have invented a new and useful Improvement in Balanced Slide-Valves, of which the following is a full, clear, and exact description.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar letters of reference indicate corresponding parts in all the figures.

Figure 1 is a sectional side elevation of my improvement. Fig. 2 is a sectional plan view of the same, taken through the broken line 00 as w a, Fig. 1. Fig. 3 is a sectional end elevation of the same.

The object of this invention is to provide balanced slide-valves constructed in such a manner as to lessen the friction and wear of such valves, and consequently to lessen'the amount of fuel required to run the engines with which the said valves are connected.

The invention consists in a balanced slidevalve with steel plates interposed between the tops of the parts of the valve and the tops of the valve-boxes, and having upwardly-proj ecting flanges at their ends fitting steam-tight into recesses in the ends of the tops of the said valve-boxes,whereby the top of the valve will be protected from steam pressure, and the wear will be taken up automatically,-as will be hereinafter fully described.

A represents the steam-cylinder, and B the piston, of a steam-engine. G is the steamchest, from the end parts of which ports D lead to the end parts of the cylinder A, and ports E lead to the exhaust-opening F. Steam is admitted into the steam-chest 0 through the inlet-opening G.

The valve is made in two parts, H, to lessen the friction-surfaces, which parts are connected by abar, I. The piston-rod J passes in through stuffing-boxes K in the ends of the steam-chest O, and is connected with the parts H of the valve by yokes L,passing around the said parts H, the sides of which are recessed to receive the said yokes and allow them to have the requisite play. The parts H of the valve have recesses M in their ends to increase the steam capacity of the steam-chest O, and have recesses N in their lower sides for the passage of the exhaust-steam from the ports D to the ports E. Each part H of the valve is placed in a valve-box, 0, having close sides and top and open ends, and which are made of a length equal to the combined length of the said part H and its stroke, so that the said part H will always be within the said valve-box O. The height of the valve-boX O is made a little less than the interior height of the valve-chest O, to form a-steam-space above the said valveboX, and the interior height of the said valvebox 0 is a little greater than the height of the part H of the valve to form a space to receive the steel plate P. Upon the ends of the steel plate P are formed upwardly projecting flanges Q, which fit steam-tight into recesses R, formed in the ends of the top of the valvebox 0, as shown in Figs. 1 and 2, so that no steam can enter between the said top and plate. By this construction the steam-pressure upon the upper edges of the flanges Q will hold the plate P down closely upon the part H of the valve, to take up the wear and prevent any downward steam-pressure from coming upon the top of the valve,and thus cause the valve to work with the least possible friction, so that there will be very little wear upon the frictionsurfaces of the valve, and so that the power required to work the valve will be reduced to a minimum.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- In a balanced slide-valve, the combination, with the parts H of the valve and the valve boxes 0, having recesses R in the ends of its top,of the steel plate P, having flanges Q upon its ends fitting into the said recesses, substantially as herein shown and described, whereby the top of the valve will be protected from steam-pressure, and the wear will be taken up automatically, as set forth.

XVILLIAM G. SMITH.

Witnesses:

JAMES T. GRAHAM, EDGAR TATE. 

